1991 Volvo 242 cold start

Computer problem
1991 Volvo 242 4 cyl Two Wheel Drive Automatic 185 kl miles

Hi, My volvo 242 starts good when cold, but does not idle up when cold thus rough idle. I have to feather the gas till warm. Many parts replaced such as
computer, mass air flow, tune-up, coolant temp, fuel
regulator, fuel pump. Could it be the cold
start injector ?

thanks,